Modular electrical boxes which may be assembled from a set of modules either as single boxes or multiple ganged box systems are known in the art, as evidenced by U.S. Patents to J. S. Ziegler, et al., U.S. Pat. No. 948,438, Feb. 8, 1910, entitled SWITCH BOX OR CASING; M. Murray, U.S. Pat. No. 1,066,215, Jul. 1, 1913, entitled ELECTRIC BOX; A. T. Kvarnstrom, U.S. Pat. No. 1,456,385, May 22, 1923, entitled FUSE BOX; E. H Lewis, U.S. Pat. No. 1,534,723, Apr. 21, 1925, entitled SECTIONAL SWITCH BOX; J. J. Johnston, U.S. Pat. No. 4,612,412, Sep. 16, 1986, entitled ELECTRICAL OUTLET BOX ASSEMBLY and R. W. Jorgensen U.S. Pat. No. 4,428,492, Jan. 31, 1984 entitled GANGABLE HOUSING; and U.S. Pat. No. 5,619,013, Apr. 8, 1997 entitled GANGABLE ELECTRICAL BOX.
This body of art, however, is deficient for retrofit use in expansion of the volume of existing electrical boxes installed at a building site to incorporate additional electrical wiring by ganging on additional box modules, particularly when such modules must rely upon the existing box for primary in-site support. Existing boxes affixed to a wall are termed anchor boxes. Such boxes have anchoring structure protruding from outer box walls for securing the boxes in place to a building support body. In a typical embodiment, such structure provides for nailing the anchor box to a stud. In other embodiments structure protruding from the walls may serve to anchor the box into a cement base or other floor material. In retrofitting an expansion box module to an anchored box to laterally form a ganged box of greater internal volume, a removable sidewall is required for replacement of an expansion box module. In the prior art the available electric expansion box configurations require other protruding structure from the expansion box for separate anchoring of the added on boxes, and thus cannot rely primarily upon interlocking joint structure between boxes for supporting the expansion box upon the originally attached anchor box. In other words, the prior art capable of retrofit ganging, in general, requires each added box to be supported by flanges or fittings extending from the boxes to secure them to building elements such as a stud or lath or for bonding to surrounding floor materials and the like.
Furthermore, such prior art modularized boxes that permit a side to be removed for retrofit replacement of a ganged-on extension box for increasing the box volume must meet electrical code requirements for added electrical wiring or accessories. In general the box volume and support stability are critical. This prior art typically requires lateral access and large open workspace for mounting a ganged-in box, which generally requires screwing and unscrewing fittings or dismount and rewiring of the anchor box. Some boxes have no removable sidewall for installing a gangable extension box in its place. Thus, retrofit of existing wiring generally requires considerable damage and mutilation to former installation sites which require wall repairs and cosmetic refinishing in the retrofit process.
Thus, the installation process has been accompanied by excessive electrician time, expense and inconvenience, part of which constitutes repair and refinishing of the installation site after an expansion module is retrofit. Furthermore, in order to retrofit electrical systems in the field, electricians are often required to order special electrical box configurations, thereby adding installation time and cost to upgrading efforts. Alternatively, they must carry on a repair truck a large inventory of specialty boxes and fittings at considerable inventory cost.
Thus, it is desirable to have a minimum number of universally useful modules on hand for immediate synthesis of different required electrical box systems, including expanded ganged box arrays of various volumes. A minimal number of such modules is thus desirable from the logistics and inventory cost viewpoint to form both single boxes and ganged arrays in order to effectively and inexpensively do a reasonable range of electrical work. While the prior art has attempted to develop modules capable of a comprehensive range of electrical utilities, they have been deficient in providing effective modular structures as a convenience to the electrician and that reduce damage to wall sites when retrofitting expanded electrical service.
As further seen by analysis of the above related prior art, there is considerable waste of resources involved in upgrading existing electrical service by adding ganged boxes. Thus, for example, the prior art rarely provides a system that reuses rather than discards a side plate removed from a standard rectangular shaped electric box to gain access for rewiring and attachment of ganged extension boxes. With stringent waste disposal laws and the necessity to salvage scrap materials, a better solution would be the development of a modular system that reduces waste.
It is accordingly a general objective of this invention to improve the status of the electrical box arts by elimination of the foregoing problems.
It is a more particular objective of the present invention to provide modular electrical box systems that are particularly advantageous for retrofit expansions of electrical service in material and labor costs, and which minimize damage to wall-sites and premises surrounding an electrical box that is being retrofit for added electrical service.
It is a primary object of this invention to provide the electrician with electrical box modular systems that will reduce installation and inventory costs both in initial electrical service installations and retrofit upgrading installations.
Further objects, advantages and features of the invention will be found throughout the following description, claims and accompanying drawings.